Capital Gains Tax Calculator
Estimate Capital Gains Tax on shares, second homes and other assets after the £3,000 annual exempt amount.
Your result
Updates as you type. Based on 2025/26 UK figures where relevant.
How this is worked out
Take the £3,000 annual exempt amount off your gain. The part that fits inside your unused basic-rate band is taxed at 18%; the rest at 24%.
Tips
- Check your tax code on every payslip. 1257L is the standard code for 2025/26; anything else deserves a quick look in your HMRC app.
- Pension contributions and salary sacrifice reduce your taxable pay, which matters most if you're near a band threshold.
- If your income is between £100,000 and £125,140, you lose personal allowance and face an effective 60% marginal rate. Pension contributions can bring it back.
Guides for this calculator
- How to Calculate Capital Gains Tax in the UK: Step-by-Step Guide
- Capital Gains Tax: Common Mistakes, Tips and FAQs
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Frequently asked questions
How does the capital Gains Tax Calculator work?
Take the £3,000 annual exempt amount off your gain. The part that fits inside your unused basic-rate band is taxed at 18%; the rest at 24%.
When does the UK tax year start?
The UK tax year runs from 6 April to 5 April the following year. Most allowances and bands reset on 6 April.
Where can I check the official rates?
GOV.UK publishes all current income tax, National Insurance and student loan rates. Our figures are based on the tax year shown on each calculator.
Is this calculator a substitute for advice?
No. It gives a clear estimate for common situations. For complex cases such as multiple incomes, benefits in kind or residency questions, speak to an accountant or HMRC.
This calculator gives an estimate for general information. It isn't financial, tax, legal or medical advice. Check official figures on GOV.UK or NHS.uk, or speak to a qualified adviser.